Terminology » Bluetooth Classic BR vs EDR PHY modes:Key Differences

Bluetooth Classic BR vs EDR PHY modes:Key Differences

bluetooth classic PHY BR EDR difference between

Introduction : Bluetooth Classic has two main physical layer modes viz. Basic Rate (BR) and Enhanced Data Rate (EDR). While both operate within the Bluetooth Classic standard, they differ significantly in terms of data rate, modulation schemes and intended applications.

BR PHY Mode

  • Introduced in Bluetooth 1.1.
  • Symbol rate: 1 Msym/s.
  • Modulation: GFSK (Gaussian Frequency Shift Keying).
  • Data rate: 1 Mbps raw.
  • Used for both data and signaling.
  • Reliable but limited throughput.

EDR PHY Mode

  • Introduced in Bluetooth 2.0 + EDR to improve data throughput.
  • Symbol rate: still 1 Msym/s (same as BR).
  • Achieves higher bit rate by changing modulation scheme.
  • Not used for link setup (BR always used first).

EDR Variants:

  1. EDR 2 Mbps

    • Modulation: π/4-DQPSK (Differential Quadrature Phase Shift Keying).
    • Doubles data throughput compared to BR.

  2. EDR 3 Mbps

    • Modulation: 8DPSK (8-ary Differential Phase Shift Keying).
    • Achieves triple throughput compared to BR.
    • More sensitive to noise/interference (lower robustness).

Key differences

FeatureBR PHYEDR 2 PHYEDR 3 PHY
SpecificationBluetooth 1.1Bluetooth 2.0 + EDRBluetooth 2.0 + EDR
Symbol rate1 Msym/s1 Msym/s1 Msym/s
ModulationGFSKπ/4-DQPSK8DPSK
Gross data rate1 Mbps2 Mbps3 Mbps
Robustnesshigh (Most reliable)GoodLower (more error prone)
Use caseLegacy, setup, controlaudio streaming, faster dataHigh speed file transfers

Conclusion: In summary, BR provides a reliable but lower-speed foundation, while EDR enhances throughput by introducing advanced modulation techniques. Together, they enabled Bluetooth Classic to support both simple control tasks and richer applications like music streaming, paving the way for the Bluetooth ecosystem we use today.